When a user is swimming, there is often a need to know many factors related to the swimming session, such as total distances, number of laps, swimming styles, stroke consistency, and/or energy expenditure. It is, however, generally difficult to estimate how many calories a user burns during a swimming session because energy expenditure depends on many factors such as speed, efficiency, swimming style, etc. Particularly, glides and strokes can correspond to different energy consumption rates, and ignoring glides can cause overestimates in energy expenditure. Accordingly, it is desirable to provide methods and systems for estimating energy expenditure of a user while swimming.